var current = "introduction";

function postback(e) {
	if (e.target) {
		var node = e.target;
	} else {
		var e = window.event
		var node = e.srcElement;
	}
	if (node.title != current && node.id != "menu") {
		switch (e.type) {
			case "mouseover": { node.style.color = "#f90"; break; }
			case "mouseout": { node.style.color = "#39f"; break; }
			case "click": {
				document.getElementById(current).style.display = "none";
				current = node.title;
				document.getElementById(current).style.display = "block";
				var menu = document.getElementById("menu").getElementsByTagName("div");
				for (i = 0; i < menu.length; i++) {
					if (menu[i].title != current) {
						menu[i].style.color = "#39f";
						menu[i].style.backgroundImage = "none";
					}
				}
				node.style.color = "#222";
				node.style.backgroundImage = "url(/lib/images/line.png)";
				break;
			}
		}
	}
}